The coupling of flow injection analysis (FIA) or high performance liquid chromatography (HPLC) techniques to inductively coupled plasma-atomic emission spectroscopy (ICP-AES) offers new and attractive approaches for the determination of elemental concentrations in a wide variety of sample matrices. Several advantages of FIA over continuous flow methods for sample introduction into the ICP have been discussed, and one of the most attractive features that FIA offers is a rapid and precise means of automating sample introduction into an ICP for simultaneous, multielement analysis at the trace, minor, and major constituent level with minimal sample consumption. The utilization of the ICP as a detector for HPLC retains most of the advantages of FIA-ICP, while providing the analyst with a powerful and versatile means of compound separation. This added dimension becomes particularly important when metal speciation is of primary interest, rather than total metal content.
To date, the coupling of FIA and HPLC to the ICP has only been accomplished using conventional cross-flow, concentric, or Babington-type pneumatic nebulizers. Limits of detection under these conditions have generally been observed to be poorer when compared to conventional continuous sample flow conditions. These limitations have been attributed to the large dead-volume and sample losses associated with conventional nebulizers, and band broadening of eluents from FIA transfer tubing or HPLC columns prior to entering the nebulizer unit.